통합 검색 | Korea Science

Kang, Sung-Sik;Chi, Se-Hwan;Hong, Jun-Hwa
- Nuclear Engineering and Technology
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- 제30권4호
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- pp.364-376
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- 1998
The statistical analysis method was applied to the evaluation of fracture toughness in the ductile-brittle transition temperature region. Because cleavage fracture in steel is of a statistical nature, fracture toughness data or values show a similar statistical trend. Using the three-parameter Weibull distribution, a fracture toughness vs. temperature curve (K-curve) was directly generated from a set of fracture toughness data at a selected temperature. Charpy V-notch impact energy was also used to obtain the K-curve by a $K_{IC}$ -CVN (Charpy V-notch energy) correlation. Furthermore, this method was applied to evaluate the neutron irradiation embrittlement of reactor pressure vessel (RPV) steel. Most of the fracture toughness data were within the 95% confidence limits. The prediction of a transition temperature shift by statistical analysis was compared with that from the experimental data.
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Kirk, Mark
- Nuclear Engineering and Technology
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- 제45권3호
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- pp.277-294
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- 2013
In the early 1980s, attention focused on the possibility that pressurized thermal shock (PTS) events could challenge the integrity of a nuclear reactor pressure vessel (RPV) because operational experience suggested that overcooling events, while not common, did occur, and because the results of in-reactor materials surveillance programs showed that RPV steels and welds, particularly those having high copper content, experience a loss of toughness with time due to neutron irradiation embrittlement. These recognitions motivated analysis of PTS and the development of toughness limits for safe operation. It is now widely recognized that state of knowledge and data limitations from this time necessitated conservative treatment of several key parameters and models used in the probabilistic calculations that provided the technical of the PTS Rule, 10 CFR 50.61. To remove the unnecessary burden imposed by these conservatisms, and to improve the NRC's efficiency in processing exemption and license exemption requests, the NRC undertook the PTS re-evaluation project. This paper provides a synopsis of the results of that project, and the resulting Alternate PTS rule, 10 CFR 50.61a.
https://doi.org/10.5516/NET.07.2013.704 인용 PDF KSCI KPUBS

Jang Min Park ;Kukhee Lim
- Nuclear Engineering and Technology
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- 제54권12호
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- pp.4522-4533
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- 2022
For severe accident assessment of reactor pressure vessel (RPV), it is important to develop an accurate model that can predict transient thermo-mechanical behavior of the RPV lower head under the given condition. The present study revisits the lower head failure with two- and three-dimensional finite element models. In particular, we aim to give clear insight regarding the effect of the three-dimensionality present in the distribution of the thickness and thermal load of the lower head. For a rigorous validation of the result, both the OLHF-1 and the OLHF-2 tests are considered in this study. The result suggests that the three-dimensional effect is not negligible as far as the failure location is concerned. The non-uniformity of the thickness distribution is found to affect the failure location and time. The thermal load, which may not be axisymmetric in general, has the most significant effect on the failure assessment. We also observe that the creep property can affect the global deformation of the lower head, depending on the applied mechanical load.
https://doi.org/10.1016/j.net.2022.08.015 인용 PDF KSCI

김현보
- 국방과기술
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- 5호통권123호
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- pp.18-27
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- 1989
정찰, 공중표적으로 출발한 UAV, RPV는 센서 및 전자공학의 비약적인 발달로 인해 이제는 대지/대함공격은 물론 전자전분에 까지 진출하려 하고 있다. 가까운 장래에 전쟁의 새로운 주역이 될 세계적인 UAV를 개발하기 위한 각국의 새로운 움직임을 살펴보기로 한다
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